Tank-to-tank connections are often required in the aerospace field, as well as other fields. For example, a tank-to-tank connection is generally needed for fuel transfer without leaks, particularly for helicopter or aircraft fuel systems. Generally, the connection between two tanks (which may be flexible material tanks or any other type of tank) is currently provided by a system that requires two flexible chimneys, a rigid sleeve, and metal clamps that are secured via screwdriver.
More specifically, prior art FIG. 1 shows one example of a prior art connection. This figure shows a first flexible chimney 1 that is first bonded to a rigid sleeve 3 on a tank. During assembly, a second flexible chimney 2 is assembled on the first flexible chimney 1 (generally using a lubricating means) and then fixed inside the tank by metal clamps 4 via a screwdriver.
The connection (fastening) process to connect the chimneys between two tanks typically takes a long time, and in some instances, lasts around fifteen minutes. Use of a screwdriver for the metal clamps during the assembly risks damaging the tanks or the flexible chimneys due to the constant pressure from screwing and unscrewing the clamps. The assembly also depends on the operator competence and strength during the assembly. This creates variability due to operator ability and the amount of force that s/he is able to put on the screws during the connection/tightening process. Additionally, during the lifetime of tanks, as the tanks are fixed by screwing, there can be a decrease of the clamping force. Additionally, after some time, due to rubber aging, the two flexible chimneys could begin to remain stuck together under the clamps, which can lead to a difficult disassembly and can add to maintenance issues. Accordingly, improvements to these fittings are desired and necessary.